●Description
●The MAX3238E/MAX3248E transceivers use Maxim"s revolutionary AutoShutdown Plus feature to achieve 10nA supply current. These devices shut down the on-board power supply and drivers when they do not sense a valid signal transition on either the receiver or transmitter inputs. This occurs if the RS-232 cable is disconnected or if the transmitters of the connected peripheral are turned off. The devices turn on again when a valid transition is applied to any RS-232 receiver or transmitter input. AutoShutdown Plus automatically achieves this power savings through its on-board circuitry, as no changes are required to the existing BIOS or operating system.
●All RS-232 inputs and outputs, as well as the logic I/O pins, have enhanced ESD protection to ±15kV. The additional ESD protection on the logic I/O pins makes the MAX3238E/MAX3248E ideal for cell phone data cable applications because it eliminates the need for costly external TransZorb or protection schemes.
●The MAX3238E/MAX3248E contain five drivers and three receivers and are 3V-powered EIA/TIA-232 and V.28/V.24 communication interfaces intended for cell phones, data cables, and modem applications. A proprietary, high-efficiency, dual charge-pump power supply and a low-dropout transmitter combine to deliver true RS-232 performance from a single +3.0V to +5.5V supply. A guaranteed data rate of 250kbps provides compatibility with popular software for communicating with personal computers.
●The MAX3238E and the MAX3248E differ only in their input logic thresholds. The MAX3238E has standard logic thresholds, while the MAX3248E has low-level logic thresholds of 0.6V to 1.2V, which are ideal for 1.8V systems.
●The transmitter inputs, FORCEON, and active-low FORCEOFF have a 400 kilohms active positive feedback resistor. Once driven to a valid logic level, they will retain this level if the driving signal is removed or goes high impedance. Unused transmitter and logic inputs may be left unconnected. The MAX3238E/MAX3248E can operate with supply voltages ranging from +3.0V to +5.5V.